If you are tired and you are at home then take that nap and do not fight it. Even a 20 minute nap can be just enough to refresh you and clear your mind. You are no good if you are tired and sluggish. If you are tired then listen to your body because it is telling you that it needs to relax and rest and needs to rejuvinate. So stop and take a break and close your eyes and put on that alarm clock if you have to but sleep!